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<FONT color="green">001</FONT>    package net.jmatrix.eproperties.monitor;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    import java.util.*;<a name="line.3"></a>
<FONT color="green">004</FONT>    <a name="line.4"></a>
<FONT color="green">005</FONT>    import net.jmatrix.eproperties.EProperties;<a name="line.5"></a>
<FONT color="green">006</FONT>    <a name="line.6"></a>
<FONT color="green">007</FONT>    /**<a name="line.7"></a>
<FONT color="green">008</FONT>     * This class monitors URLs for changes (via URL dependent methods) and will<a name="line.8"></a>
<FONT color="green">009</FONT>     * reload the properties if the URLs have changed.  &lt;p&gt;<a name="line.9"></a>
<FONT color="green">010</FONT>     * <a name="line.10"></a>
<FONT color="green">011</FONT>     * This is a single monitor thread.  This thread monitors all properties<a name="line.11"></a>
<FONT color="green">012</FONT>     * files in a single thread - as there may be many files.  The thread<a name="line.12"></a>
<FONT color="green">013</FONT>     * is initialized internally if a single properties object registers<a name="line.13"></a>
<FONT color="green">014</FONT>     * itself.  Its delay time is globally configurable.<a name="line.14"></a>
<FONT color="green">015</FONT>     *<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    public class EPropertiesMonitor extends Thread {<a name="line.17"></a>
<FONT color="green">018</FONT>       <a name="line.18"></a>
<FONT color="green">019</FONT>       /** Singleton instance. */<a name="line.19"></a>
<FONT color="green">020</FONT>       private static EPropertiesMonitor instance=null;<a name="line.20"></a>
<FONT color="green">021</FONT>       <a name="line.21"></a>
<FONT color="green">022</FONT>       /** The delay time between checking files. */<a name="line.22"></a>
<FONT color="green">023</FONT>       private long delay=20000; // 20 s<a name="line.23"></a>
<FONT color="green">024</FONT>       <a name="line.24"></a>
<FONT color="green">025</FONT>       /** */<a name="line.25"></a>
<FONT color="green">026</FONT>       private volatile boolean shutdown=false;<a name="line.26"></a>
<FONT color="green">027</FONT>       <a name="line.27"></a>
<FONT color="green">028</FONT>       /** */<a name="line.28"></a>
<FONT color="green">029</FONT>       private List&lt;EProperties&gt; monitoredProperties=new ArrayList&lt;EProperties&gt;();<a name="line.29"></a>
<FONT color="green">030</FONT>       <a name="line.30"></a>
<FONT color="green">031</FONT>       /** Singleton constructor.  */<a name="line.31"></a>
<FONT color="green">032</FONT>       private EPropertiesMonitor() {<a name="line.32"></a>
<FONT color="green">033</FONT>          setName("EPropertiesMonitor");<a name="line.33"></a>
<FONT color="green">034</FONT>       }<a name="line.34"></a>
<FONT color="green">035</FONT>       <a name="line.35"></a>
<FONT color="green">036</FONT>       /** Execution method. */<a name="line.36"></a>
<FONT color="green">037</FONT>       public void run() {<a name="line.37"></a>
<FONT color="green">038</FONT>          try {<a name="line.38"></a>
<FONT color="green">039</FONT>             while (!shutdown) {<a name="line.39"></a>
<FONT color="green">040</FONT>                // 1) sleep a bit.<a name="line.40"></a>
<FONT color="green">041</FONT>                try {<a name="line.41"></a>
<FONT color="green">042</FONT>                   sleep(delay);<a name="line.42"></a>
<FONT color="green">043</FONT>                } catch (InterruptedException ex) {<a name="line.43"></a>
<FONT color="green">044</FONT>                   // this is expected at times.  and does not hurt.  no log.<a name="line.44"></a>
<FONT color="green">045</FONT>                }<a name="line.45"></a>
<FONT color="green">046</FONT>                <a name="line.46"></a>
<FONT color="green">047</FONT>                // 2) check reload<a name="line.47"></a>
<FONT color="green">048</FONT>                try {<a name="line.48"></a>
<FONT color="green">049</FONT>                   synchronized (monitoredProperties) {<a name="line.49"></a>
<FONT color="green">050</FONT>                      int size=monitoredProperties.size();<a name="line.50"></a>
<FONT color="green">051</FONT>                      <a name="line.51"></a>
<FONT color="green">052</FONT>                      log("Monitoring "+size+" EProperties objects.");<a name="line.52"></a>
<FONT color="green">053</FONT>                      <a name="line.53"></a>
<FONT color="green">054</FONT>                      for (int i=0; i&lt;size; i++) {<a name="line.54"></a>
<FONT color="green">055</FONT>                         EProperties props=monitoredProperties.get(i);<a name="line.55"></a>
<FONT color="green">056</FONT>                         if (props.isSourceModified())<a name="line.56"></a>
<FONT color="green">057</FONT>                            props.reload();<a name="line.57"></a>
<FONT color="green">058</FONT>                      }<a name="line.58"></a>
<FONT color="green">059</FONT>                   }<a name="line.59"></a>
<FONT color="green">060</FONT>                } catch (Exception ex) {<a name="line.60"></a>
<FONT color="green">061</FONT>                   log("Error reloading properties.", ex);<a name="line.61"></a>
<FONT color="green">062</FONT>                }<a name="line.62"></a>
<FONT color="green">063</FONT>             }<a name="line.63"></a>
<FONT color="green">064</FONT>          } catch (Throwable t) {<a name="line.64"></a>
<FONT color="green">065</FONT>             log("Error in EPropertiesMonitor!!  Thread is exiting.", t);<a name="line.65"></a>
<FONT color="green">066</FONT>          }<a name="line.66"></a>
<FONT color="green">067</FONT>       }<a name="line.67"></a>
<FONT color="green">068</FONT>       <a name="line.68"></a>
<FONT color="green">069</FONT>       static final void log(String s) {<a name="line.69"></a>
<FONT color="green">070</FONT>          System.out.println (s);<a name="line.70"></a>
<FONT color="green">071</FONT>       }<a name="line.71"></a>
<FONT color="green">072</FONT>       <a name="line.72"></a>
<FONT color="green">073</FONT>       static final void log(String s, Throwable t) {<a name="line.73"></a>
<FONT color="green">074</FONT>          System.out.println (s);<a name="line.74"></a>
<FONT color="green">075</FONT>          t.printStackTrace();<a name="line.75"></a>
<FONT color="green">076</FONT>       }<a name="line.76"></a>
<FONT color="green">077</FONT>       <a name="line.77"></a>
<FONT color="green">078</FONT>       public static final EPropertiesMonitor getInstance() {<a name="line.78"></a>
<FONT color="green">079</FONT>          synchronized(EPropertiesMonitor.class) {<a name="line.79"></a>
<FONT color="green">080</FONT>             if (instance == null) {<a name="line.80"></a>
<FONT color="green">081</FONT>                synchronized(EPropertiesMonitor.class) {<a name="line.81"></a>
<FONT color="green">082</FONT>                   instance=new EPropertiesMonitor();<a name="line.82"></a>
<FONT color="green">083</FONT>                   instance.start();<a name="line.83"></a>
<FONT color="green">084</FONT>                }<a name="line.84"></a>
<FONT color="green">085</FONT>             }<a name="line.85"></a>
<FONT color="green">086</FONT>          }<a name="line.86"></a>
<FONT color="green">087</FONT>          return instance;<a name="line.87"></a>
<FONT color="green">088</FONT>       }<a name="line.88"></a>
<FONT color="green">089</FONT>       <a name="line.89"></a>
<FONT color="green">090</FONT>       private void internalAdd(EProperties pr) {<a name="line.90"></a>
<FONT color="green">091</FONT>          monitoredProperties.add(pr);<a name="line.91"></a>
<FONT color="green">092</FONT>       }<a name="line.92"></a>
<FONT color="green">093</FONT>       <a name="line.93"></a>
<FONT color="green">094</FONT>       ////////////// Public, Static API //////////////<a name="line.94"></a>
<FONT color="green">095</FONT>       public synchronized static void add(EProperties props) {<a name="line.95"></a>
<FONT color="green">096</FONT>          // getInstance().add(props);<a name="line.96"></a>
<FONT color="green">097</FONT>          EPropertiesMonitor monitor=getInstance();<a name="line.97"></a>
<FONT color="green">098</FONT>          monitor.internalAdd(props);<a name="line.98"></a>
<FONT color="green">099</FONT>       }<a name="line.99"></a>
<FONT color="green">100</FONT>       <a name="line.100"></a>
<FONT color="green">101</FONT>       public synchronized static void setMonitorDelay(long millis) {<a name="line.101"></a>
<FONT color="green">102</FONT>          getInstance().delay=millis;<a name="line.102"></a>
<FONT color="green">103</FONT>       }<a name="line.103"></a>
<FONT color="green">104</FONT>       <a name="line.104"></a>
<FONT color="green">105</FONT>       public synchronized static void shutdown() {<a name="line.105"></a>
<FONT color="green">106</FONT>          if (instance != null) {<a name="line.106"></a>
<FONT color="green">107</FONT>             instance.shutdown=true;<a name="line.107"></a>
<FONT color="green">108</FONT>             instance.interrupt();<a name="line.108"></a>
<FONT color="green">109</FONT>             instance=null;<a name="line.109"></a>
<FONT color="green">110</FONT>          }<a name="line.110"></a>
<FONT color="green">111</FONT>       }<a name="line.111"></a>
<FONT color="green">112</FONT>    }<a name="line.112"></a>




























































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